In order to increase product quality and to minimize energy consumption and impact on the environment, it is necessary to optimize the food process design and operation. Therefore, the aim of this work was to study the optimization feasibility of the milk pasteurization process using a general process simulator (ProSimPlus). To simulate the pasteurization process, a simulation flowsheet was developed using the simulator, and a database was built in the simulator with the values and/or functions to estimate the necessary physical properties of the whole milk. Using the ProSimPlus utilities (control units) an objective function was set up in order to optimize the process design and the process operation of the milk pasteurization process. For that purpose a ProSimPlus module (optimization: OPTI) was used. By introducing physical properties related to other products and redefining the objective function the application of this general simulator could be extended in the Food Industry. (C) 2009 Elsevier Ltd. All rights reserved.